We have changed the way these applets are launched.

Here's why...

More browsers are removing the ability to run embedded Java applets (such as these data viewers), so now we are launching them using JavaWS
(Java Web Start).

Our applets will run outside the browser, but they are still subject to the same sandbox restrictions as when they are run within the browser.

The data viewer links will download a small app that is used to launch the applet -- a ".jnlp file"
(Java Network Launching Protocol).
Some browsers will allow you to launch the app directly. All browsers will let you save these files, which you can then open like you would any app.